Implemented hyperrectangle class
Added documentation
Added a specialisation for rectangles
Added rectangle test
Specialization for boxes
Implemented point and rectangle overlap
Documentation improvement
Renamed isIn() to contains()
Added some tests which currently fail (not good!)
Fixed rectangles not working with negative extent
Added constexpr where appropriate
Implemented K-d tree range search
Fixed some formatting issues
Added operator[] to prepare k-d trees with volumetric objects
Added note
Added isSimilar() method to class Hyperrectangle
Comment clarification
Fixed comment
Comment clarification
Merge remote-tracking branch 'origin/master' into Renderer